Hi, are you still experiencing this issue? Wondering a couple things:
- What file type are you trying to create the proof with?
- Where are you on your space? In Setup > Customer Info, you can see your storage and how much space you've used. The storage is crazy high but wondering if you're near the threshold or something.
- This sounds strange, but also try clearing your cache and reuploading the proof - an uncleared cache can cause the craziest things in WF.
If this helped you, please mark correct to help others : )